A Fast Distance Relay Based on Variable-Structure GDSC

This work presents a new Symmetrical Component Distance Relay (SCDR) algorithm based on Variable-Structure Generalized Delayed Signal Cancelation (VS-GDSC) for components estimation. The SCDR faces the technological limits for protective devices based on harmonic components: the need for faster analysis implies the use of a temporally narrower data window, making it difficult to evaluate the signal in the frequency domain and, consequently, the identification of specific harmonic components. To overcome this condition, we assembled, fitted and improved three independent algorithms: GDSC-based SCDR, VS-GDSC and a fast magnetizing current discriminator. As a result, the new VS-GDSC-based SCDR presents a reduction in the response time around 25 % of the fundamental period for the short-circuit test cases, relative to the GDSC-based SCDR.